The invention relates to a laser system for thermal, non ablative treatment of mucosa tissue.
Mucosa is the moist tissue that in addition to some human organs lines body cavities that are exposed to the external environment. They are at several places continuous with skin: at the nostrils, the mouth, the lips, the eyelids, the ears, the genital area, and the anus.
There is a number of health problems that are caused by a deteriorating laxity, elasticity and tightness of mucous membranes and the underlying adjacent tissues (muscles etc.) The following are some of the most common problems: a) involuntary loss of urine called urinary incontinence (UI) among women; b) loss of anal sphincter control leading to the unwanted or untimely release of feces or gas called anal or fecal incontinence; c) vaginal relaxation and the loss of sexual gratification in women and d) snoring.
a) Urinary Incontinence in Women
Millions of women experience involuntary loss of urine called urinary incontinence (UI). Some women may lose a few drops of urine while running or coughing. Others may feel a strong, sudden urge to urinate just before losing a large amount of urine. Many women experience both symptoms. UI can be slightly bothersome or totally debilitating. For some women, the risk of public embarrassment keeps them from enjoying many activities with their family and friends. Urine loss can also occur during sexual activity and cause tremendous emotional distress. Women experience UI twice as often as men. Pregnancy and childbirth, menopause, and the structure of the female urinary tract account for this difference. But both women and men can become incontinent from neurologic injury, birth defects, stroke, multiple sclerosis, and physical problems associated with aging. Older women experience UI more often than younger women. But incontinence is not inevitable with age. UI is a medical problem. Incontinence often occurs because of problems with muscles that help to hold or release urine.
The body stores urine—water and wastes removed by the kidneys—in the bladder, a balloon-like organ. The bladder connects to the urethra, the tube through which urine leaves the body. During urination, muscles in the wall of the bladder contract, forcing urine out of the bladder and into the urethra. At the same time, sphincter muscles surrounding the urethra relax, letting urine pass out of the body.
Worldwide urinary incontinence (UI) is a common problem that affects between 17% to 45% of adult women, often reflected in a deterioration of their social life. The high cost of care for UO, which exceeds 2% of health expenditures in the United States makes this syndrome a public health concern. The most common is Stress Ur. Incontinence (SUI), accounting for 48% of cases, followed by Urge Ur. Incontinence (UUI), caused by an overactive bladder and representing 17% of UI cases. Due to social embarrassment, the taboo or lack of awareness of potential treatments, only a minority of women with UI seek professional help.
One type of incontinence will occur if the sphincter muscles are not strong enough to hold back urine. Treatments involve injections and surgery. A variety of bulking agents, such as collagen and carbon spheres, are available for injection near the urinary sphincter. The doctor injects the bulking agent into tissues around the bladder neck and urethra to make the tissues thicker and close the bladder opening to reduce stress incontinence. A latest surgical technique that uses a polypropylene mesh as prosthetic material reduces the recurrences from 50 to 3%. However, the prosthetic material is autologous and may be rejected. In addition, any surgical procedure (including mesh technique) requires operating theatre, which involves high effort and reduces acceptance by the patient.
b) Fecal Incontinence
Fecal incontinence is one of the most psychologically and socially debilitating conditions in an otherwise healthy individual. Fecal incontinence is a syndrome that involves the unintentional loss of solid or liquid stool. Many definitions of fecal incontinence exist, some of which include flatus (passing gas), while others are confined to stool. True anal incontinence is the loss of anal sphincter control leading to the unwanted or untimely release of feces or gas.
Fecal incontinence has many etiologies. One or a combination of several factors can lead to the inability to control passage of stool or flatus. Vaginal delivery is widely accepted as the most common predisposing factor to fecal incontinence in an otherwise young and healthy woman. Vaginal delivery may result in internal or external anal sphincter disruption, or may cause more subtle damage to the pudendal nerve through overstretching and/or prolonged compression and ischemia.
Many studies support the theory that mechanical sphincter disruption contributes to fecal incontinence. Several surgical procedures are performed for the treatment of anal incontinence. The type of procedure used is based on the patient history, physical examination findings, and results of diagnostic evaluation. The current philosophy in pelvic reconstructive surgery is restoration of normal anatomy. Usually, sphincter complex defects are secondary to obstetric injury, fistula repair, or lateral internal sphincterotomy. The standard procedure for anal incontinence due to anal sphincter disruption is the anterior overlapping sphincteroplasty.
When fecal incontinence persists after medical and surgical therapies have failed, a colostomy may be considered. This converts a perineal stoma into a manageable abdominal stoma and removes the constant fear of public humiliation.
c) Deterioration and Relaxation of Vaginal Tissues
Vaginal relaxation is the loss of the optimum structural architecture of the vagina. This process is generally associated with natural aging and specially affected by childbirth, whether vaginal or not. Multiple pregnancies increase even more the alteration of these structures. During the vaginal relaxation process, the vaginal muscles become relaxed with poor tone, strength, control and support. The internal and external vaginal diameters can greatly increase with a significant stretching of vaginal walls. Under these circumstances the vagina is no longer at its physiologically optimum sexual functioning state. William H. Masters, M.D. and Virginia E. Johnson pioneered studies that concluded that sexual gratification is directly related to the amount of frictional forces generated during intercourse. Friction is a function of the vaginal canal diameter, and when this virtual space is expanded it can lead to reduction, delay or inexistence of orgasms. Thus, vaginal relaxation has a detrimental effect on sexual gratification because of the reduction of frictional forces that diminish sexual pleasure.
Several approaches have been developed to address this issue. The most common current technique utilizes a surgical procedure that requires the cutting and rearrangement of vaginal and peripheral tissue in order to reduce the size of the canal. Operating on or near sensitive vaginal tissue is inherently risky and can cause scarring, nerve damage and decreased sensation. Furthermore, patients require an extended recovery period.
d) Snoring
Snoring is the audible vibration of respiratory structures (inside oral cavity—soft palate and uvula) due to obstructed air movement during breathing while sleeping. In some cases the sound may be soft, but in other cases, it can be rather loud and quite unpleasant. Generally speaking, the structures involved are the uvula and soft palate.
Snoring is known to cause sleep deprivation to snorers and those around them, as well as daytime drowsiness, irritability, lack of focus and decreased libido. It has also been suggested that it can cause significant psychological and social damage to sufferers. Multiple studies reveal a positive correlation between loud snoring and risk of heart attack (about +34% chance) and stroke (about +67% chance).
Surgery is one of the methods that are currently used for correcting social snoring. Some procedures, such as uvulopalatopharyngoplasty, attempt to widen the airway by removing tissues in the back of the throat, including the uvula and pharynx. These surgeries are quite invasive, however, and there are risks of adverse side effects. The most dangerous risk is that enough scar tissue could form within the throat as a result of the incisions to make the airway narrower than it was prior to surgery, diminishing the airspace in the velopharynx.
From US 2007/0265606 A1 an apparatus and method are known, using fractional light based treatment to shrink soft tissue in the mouth of throat to reduce obstruction of the airways for patients suffering from obstructive sleep apnea. A light delivering probe with scanning optics can be used to deliver treatment. Both ablative and non ablative laser light treatments are described. While the ablative laser treatment falls into the above mentioned surgery scenario with all drawbacks, a non ablative treatment has several advantages. When using non ablative lasers, tissue is coagulated to cause shrinkage, but tissue is not removed. The overall impact and burden on the patient's organism is reduced.
However, there are some significant limitations when applying non ablative laser treatment to soft tissue, in particular to mucosa tissue. A laser induced heating has to be provided in the mucosa tissue without overheating to prevent tissue damage and ablation. Heating of the underlying tissue layers has to be minimized. Namely, at high laser powers, the laser tissue interaction can become non-linear leading to ionization and optical breakdown, which may result in an undesirable damage to the tissue. Further, since a minimally invasive, non-ablative, and purely thermal treatment of mucosa is desired the fluence F of the laser must be below or close to the ablation threshold fluence. The fluence is defined as energy density: F=E/A where E is the energy of the laser pulse, and A is the spot size area. Usually it is calculated in J/cm2. The ablation threshold depends on the laser wavelength, and is lower for more strongly absorbed laser wavelengths. Strongly in water absorbed laser wavelengths are above 1.9 μM, as e.g. generated by erbium doted lasers with a wavelength of 2.79 μm or 2.94 μm. This is the reason, why US 2007/0265606 A1 proposes erbium doted lasers for ablation scenarios only, while the wavelength for non ablative treatments is taken as 1.9 μm or below. In summary, laser power, fluence and wavelength are limited, which reduces efficiency of a laser based non ablative mucosa treatment.
The invention has the object to provide means and a method for non ablative treatment of soft tissue, in particular of mucosa tissue, with improved efficiency and minimized impact on the patient's organism.